CALCULI, OR STONES, IN THE URINARY TRACT IS A RECURRING PROBLEM, AFFECTING NEARLY 800,000 IN THE U.

CALCULI, OR STONES, IN THE URINARY TRACT IS A RECURRING PROBLEM, AFFECTING NEARLY 800,000 IN THE U.S. ANNUALLY. INCISIONS TO REMOVE URINARY CALCULI ARE HIGHLY TRAUMATIC, CREATING TISSUE DAMAGE, PAIN, AND POSTOPERATIVE DISCOMFORT. RECENT ADVANCES IN TECHNOLOGY REDUCE TRAUMA BY MINIMIZING THE NEED FOR SURGERY. LASER LITHOTRIPSY HAS IMMENSE APPEAL, BUT A USEFUL DEVICE HAS NOT BEEN AVAILABLE. THE MASSACHUSETTS GENERAL HOSPITAL AND CANDELA CORPORATION IN A JOINT EFFORT HAVE DEVELOPED AN EXCELLENT LITHOTRIPTOR BASED ON A FLASHLAMP-EXCITED DYE LASER. IT WILL FRAGMENT ALL TYPES OF STONES, AND THE SIZE OF THE DEBRIS CAN BE ADJUSTED AT WILL^FROM SILT-LIKE TO PEBBLE-LIKE OR TO GROSS FRAGMENTS. THE DEBRIS DOES NOT COME OFF AT HIGH VELOCITIES TO DAMAGE THE MUCOSA, AND THE LASER BEAM WILL NOT DAMAGE THE MUCOSA IF THE BEAM IS INADVERTENTLY DIRECTED AGAINST THE MUCOSA. THIS LASER, COMBINED WITH A TRANSURETHRAL FIBER OPTIC PROBE, WILL REACH CALCULI IN THE URETER AND THE LOWER RENAL CAVITY REGIONS NOT ACCESSIBLE TO THE SHOCK WAVE LITHOTRIPTOR. GRANT FUNDS WILL BE USED TO CONDUCT CLINICAL TESTS IN VIVO, AND TO FURTHER DEVELOP THE OPTICAL OR LASER